Diesel Gen-set Operation Instructions
79
below.
Disconnect wires F1 and F2 (or F+ and F- of SE350) of excitation stator (magnetic
field) from AVR, and supply power to F1 and F2 (or F+ and F- of SE350) with a 12V
DC power source.
Start the Gen-set and operate at rated speed.
Measure voltage at primary output terminals U, V and W;
5.3.1 Voltage Balance of Primary Output Terminal
1) If the measured voltage is generally balanced with the unbalance index within
1% and within ±10% of rated voltage of alternator, all excitation windings, main
windings and main rotating diodes are sound, and AVR or transformer control
may have problems. Test AVR according to the following procedures:
2) Remove lead of magnetic field from terminals F1 and F2 (or F+ and F-) of
AVR;
3) Connect a 60W, 240V bulb between terminals F1 and F2 (or F+ and F-) of
AVR;
4) Rotate voltage control potentiometer on AVR clockwise to the end;
5) Connect 12V1.0A DC power source to F1 and F2 (or F+ and F-) of lead of
magnetic field. Note that positive electrode is connected to F1 (F+);
6) Start the Gen-set and operate at rated speed;
7) Inspect whether the deviation of output voltage of Gen-set is within ±10% of
rated voltage.
Voltage on the terminal 7-8 of AVR (or terminal 3-4 of SE350) shall be 170-250V. If
output voltage of alternator is normal while that on terminal 7-8 (or terminal 3-4 of
SE350) is too low, inspect the connection between auxiliary lead and main terminal.
The bulb between F1 and F2 (F+ and F- of SE350) shall be continuously on. Rotate
“voltage regulation” control potentiometer to the end, and the light on AVR plate shall
be off or dim.
If the light on AVR plate is on, it indicates that AVR has been damaged and shall be
replaced.
Note: rotate “voltage regulation” control potentiometer counter-clockwise to the
end after the above test.
